We’ve heard from multiple sources that Twitter is likely to have
a big-time partner for such a service: Apple. Specifically,
we’re hearing that Apple’s new iOS 5 will come with an option
to share images to Twitter baked into the OS. This would be
similar to the way you can currently share videos on YouTube with
one click in iOS. Obviously, a user would have to enable this
feature by logging in with their Twitter credentials in iOS. There
would then be a “Send to Twitter” option for pictures stored
on your device.

So close to the bigger story, but yet so far. Imagine what else the system could provide if your Twitter account was a system-level service.